NSDictionaryOfVariableBindings in Swift using Mirror 😁

Dictionary+Tuples.swift

extension Dictionary {
    /**
     Create a `Dictionary<Key, Pair>` from the provided `Sequence` of tuples
     
     - parameter pairs: The `Sequence` of tuples used to create the `Dictionary<Key, Pair>`
     */
    init(pairs: [(Key, Value)]) {
        var result = Dictionary<Key, Value>(minimumCapacity: pairs.count)
        for (key, value) in pairs {
            result[key] = value
        }
        self = result
    }
}

UIView+ViewBindings.swift

extension UIView {
    private typealias BindingPair = (key: String, value: UIView)
    
    /** 
     Performs the same function as `NSDictionaryOfVariableBindings` (which is not available in Swift)
     */
    func viewBindings() -> [String: UIView] {
        let mirror = Mirror(reflecting: self)
        
        let pairs: [BindingPair] = mirror.children.flatMap { child in
            guard
                let label = child.label,
                let view = child.value as? UIView
                else { return nil }
            
            return (label, view)
        }
        
        return Dictionary<String, UIView>(pairs: pairs)
    }
}

usage.swift

class MyViewController: UIViewController {
  private var label: UILabel = { ... }
  private var textField: UITextField = { ... }
  private var button: UIButton = { ... }
  
  override func updateConstraints() {
    let bindings = self.viewBindings()
    
    /*
    bindings = [
      "label": self.label,
      "textField": self.textField,
      "button": self.button,
    ]
    */
    
    // apply constraints...
  }
}